Okay so i have not read through all of these posts, so sorry if this has been stated previously. But there IS a way to turn off the "Remote Left in Vehicle (Triple Chime)" and "Engine Still Running"
With the vehicle running go to settings --> Vehicle --> Remote Lock, Unlock, Start --> Remote Left in Vehicle Alert (at the bottom) --> Turn off.
This will turn off both alarm chimes. Hope this helps and works for everyone. I have only tried this on a Tahoe but it should be available to everyone with newer infotainment systems across all brands.
i turned that off a while back & it still honks when leaving vehicle w/ key on me, as others are having issue with.